DFLer Al Franken's 225-vote lead in the marathon U.S. Senate recount was unanimously certified Monday by the state Canvassing Board, prompting attorneys for Republican Norm Coleman to immediately declare that they will challenge the results in court.

In a brief statement outside his Minneapolis townhouse, Franken said he was humbled and proud to be "the next senator from Minnesota," even as he acknowledged that the legal wrangling probably isn't over.

"Whether you voted for me or not, I want every Minnesotan to hear this: I work for you now, and I will work hard to earn your confidence," Franken said, declining to say when he would leave for the nation's capital.

The lawsuit that Coleman's attorneys said they would file today is called an election contest. It will prevent Gov. Tim Pawlenty and Secretary of State Mark Ritchie, under state law, from officially certifying Franken's election until the legal process has run its course.

No one knows how long that might take, but Coleman attorney Fritz Knaak said their case will pivot in part on constitutional issues, such as the equal protection clause, that typically are decided by the U.S. Supreme Court.

With Coleman's Senate term officially ended and no one yet positioned to take the seat, Minnesota is left with a single senator just as Congress is expected to grapple with the nation's financial meltdown. Congress convenes today.

Video (01:19): More from Al Franken

The Coleman campaign's last hope to postpone the board's action had crumbled earlier Monday when the Minnesota Supreme Court rejected its petition to order the review of 654 rejected absentee ballots that the campaign said appeared to be validly cast.

Those ballots, which had been labeled as properly rejected by local election officials, were left out of the pool of ballots counted Saturday that boosted Franken's margin from 49 to 225. They will be key to Coleman's legal contest, along with up to 150 ballots in DFL-leaning precincts that the campaign said were counted twice, and 133 Minneapolis votes that were counted (based on the Election Day tally) though the actual ballots couldn't be found during the hand recount.

Results, not winner, certified

Two months after the election and nearly seven weeks after the recount began, the board took less than 10 minutes to certify final results showing Franken with 1,212,431 votes and Coleman with 1,212,206.

Ritchie made it clear that the board wasn't declaring a winner, just certifying the results emerging from the process of recounting about 2.9 million undisputed ballots, thousands of challenged votes and hundreds of wrongly rejected absentee ballots.

The four judicial members who joined Ritchie on the board each praised the secretary of state and his staff for their work, and said they were satisfied that all valid votes had been counted "at least within the confines of the law," said Ramsey County District Judge Edward Cleary.

Minnesota Chief Justice Eric Magnuson called the recount "an important and historic effort" of such a scale that it shouldn't be expected to happen "without a few squeaks and protests." Ramsey County Chief District Judge Kathleen Gearin called the recount fascinating, occasionally frustrating and always exciting.

"If we have made any [mistakes] -- and we probably have -- our mistakes have been the mistakes of the warm-hearted, and the mistakes of the honest-hearted, and the mistakes of the good-hearted, just like the people of Minnesota," she said.

In rejecting Coleman's request to reconsider the 654 ballots during the recount, the Supreme Court did not address the merits of his claim that the ballots may have been wrongly rejected. Instead, it said he could later pursue a lawsuit to make his case.

Any court contest must be filed within seven days. It would be held in Ramsey County District Court and presided over by a three-judge panel.

The Supreme Court had previously ruled that county elections officials and the two campaigns must agree on which rejected absentee ballots should be included. They agreed to include 933 that the counties said were improperly rejected because of clerical errors or other reasons.

When those ballots -- which came disproportionately from DFL-leaning precincts -- were counted over the weekend, Franken's lead rose to 225.

Coleman last week asked the court to direct the counties to send all rejected absentee ballots to Ritchie, so he and the two campaigns could review them and jointly decide which to include in the recount.

The 654 absentee ballots that the campaign referred to in its request are mostly from rural and suburban areas of the state where Coleman ran well.

In an opinion written by Justice Alan Page, the court noted that it had required unanimity among the campaigns and counties on which absentee ballots would be included and which excluded.

"Local election officials have acted diligently ... and together with the candidates have agreed upon more than 900 rejected absentee ballots, which have now been opened and counted," the opinion said.

Video (02:25): Al Franken speaks

Criticism, deflection

Coleman attorney Tony Trimble accused unnamed members of Ritchie's office of engaging in partisan acts during the recount, but Ritchie deflected the criticism.

"We are not spending any time in responding to personal attacks," he said.

He pointed out that 95 percent of the Canvassing Board's decisions, including the most significant ones, were unanimous.

After the board's meeting, Franken recount attorney Marc Elias said: "Today is a great day for the people of Minnesota. I can now say, with no uncertainty left, that Al Franken has won this election by 225 votes, [and] that he will be the next senator from the state of Minnesota, and that this process worked."

While sidestepping questions about the upcoming legal challenge, Elias told reporters that the Coleman campaign's success rate in court actions during the recount was "not particularly good."

In his statement, Franken praised the recount process as fair and thorough, and he expressed sympathy for Coleman and his family.

"I know this is not an easy day for [them], and I know that because Franni [his wife] and I and our kids had plenty of time over the last couple months to contemplate what this would be like if the election turned out differently," he said. He added that he hoped to ask Coleman's help to ensure a smooth transition of constituent services.

Video (01:05): Al Franken reacts

"For our state, today marked the end of a long process that will forever be a part of Minnesota history," Franken said.

Trimble, however, begged to differ. "This process isn't at the end," he said. "It is now just at the beginning."

Kevin Duchschere is the metro team leader for the Star Tribune's Suburbs team, supervising six reporters who cover the metro area outside Minneapolis and St. Paul. He has worked in the newsroom since 1986 covering St. Paul City Hall, the Legislature and four metro area counties including Hennepin and Ramsey, and also worked several years as a general assignment reporter. He was St. Paul bureau chief from 2005 to 2007. His specialties include local government and politics.

A federal judge who described himself as disgusted by Michael Flynn's behavior upended a straightforward sentencing hearing, postponing punishment for President Donald Trump's first national security adviser and telling him in a stinging rebuke, "Arguably you sold your country out."

President Donald Trump appeared to back off his demand for $5 billion to build a border wall, signaling for the first time that he might be open to a deal that would avoid a partial government shutdown.